pic: 3D Print Limit Switch CFiber

[zcohen]

I wonder how much of a difference there is between the CF/PLA and CF/ABS?

How quickly are your nozzles deteriorating and are you lubricating them between and during prints? I have run almost 2 spools and not had a problem with my nozzles yet. I know it is a matter of time but am wondering what the contributing factors might be.

Thats a good question on the differences between the two. Sadly I cant test that as I'm not set up for ABS.

I replace my nozzle after every roll. It may be a bit excessive, but I start to notice a bit of a drop in quality after a roll when switching back to PLA. I could get another half roll or so of CF out of it, but rather be safe when it comes to quality of print, and its easy to say "after a roll, replace".


By the way, your quote in your signature was said by Muhammad Ali. Awesome quote. Have it in big letters on my wall in my classroom

[Cothron Theiss]

Originally Posted by rsegrest

In my room it likes the sides and front closed with the top off. If it is exceptionally cold I put the top on to keep cold drafts from getting in and messing up the job.

I use an Adinia H800 that gave me fits until I built an enclosure that just slides over the top of the whole printer. I know the Makergear M2 does not come with an enclosure, so I'd say that Kevin Sevcik could eliminate a lot of this delamination issues by building one.

[rsegrest]

Originally Posted by zcohen

By the way, your quote in your signature was said by Muhammad Ali. Awesome quote. Have it in big letters on my wall in my classroom

I read that somewhere but could never find solid proof that he was the one that originally said it. Would love to find original sourcing.

Also, I understand the replacing nozzle. I too have extras for when mine does wear out.

[lovelj]

Very cool part. Cothran should be familiar with this. He works in our lab.

A little bit more information. We've printed with carbon fiber reinforced ABS for about 5 years. It's a game changer.

First, the carbon fiber (if done right) increases strength, stiffness, thermal conductivity and (most importantly) reduces the coefficient of thermal expansion. We've printed complex parts on a Solidoodle with 20% CF ABS, printed the exact same thing out of ABS on our Fortus 900 and compared geometrically with our laser scanner. CF ABS on a Solidoodle is more accurate than ABS on a Fortus. In a nutshell, good material in a crappy machine beats crappy material in a good machine. You don't need an oven to control residual stress, warp and curl. We've done this on big machines (google Big Area Additive Manufacturing). Carbon fiber reinforced thermoplastics is secret sauce in the BAAM machines. We've printed parts 20 feet long with no distortion.

Second, the fact that someone's strength went down tells me the fiber isn't wetting out well with the base material. All carbon fibers have sizing (or chemistry) on their outer surface that impacts their ability to fuse with a secondary material. If you are using carbon fiber that is sized to interface with resins (typical for aerospace), it won't wet out well and you'll get poor adhesion between the fiber and thermoplastic. I'd suggest making your own filament and get pellets from someone like Techmer. You can get the loading anywhere from 5% up to 50%. 20% to 30% seems to be the sweet spot. We get 2 to 3X increase in strength and 8X increase in stiffness. Cost wise, 20% CF ABS is about $5/lb. PolyOne sells good material as well. Another material that is very interesting is PLA with Bamboo. We printed some large parts with 10% bamboo that turned out beautiful. Getting ready to try 20% bamboo.

In terms of properties, realize that they will be anisotropic. All the fibers line up with the bead (the nozzle acts like a funnel). So you're strength goes up in the bead direction but the best you'll get is about 80% to 90% of the base thermoplastic properties in the bead to bead and z-strength.

All in all, if you get the fiber with about 20% CF, you'll overcome a lot of the warp and curl problems.

Thanks for sharing.

[rsegrest]

Originally Posted by lovelj

We printed some large parts with 10% bamboo that turned out beautiful. Getting ready to try 20% bamboo.

So. Did you get the part printed and can you post a pic? May be purchasing a new printer and before I jump all off into PLA I'd like to see how your PLA bamboo came out.

[Cothron Theiss]

Originally Posted by rsegrest

So. Did you get the part printed and can you post a pic? May be purchasing a new printer and before I jump all off into PLA I'd like to see how your PLA bamboo came out.

Lonnie (lovelj) can speak more to the specifics of the bamboo print (Or would it be BAAMboo?), but I can say from an aesthetics and basic structural standpoint, it is wonderful. I can maybe get a picture of one of the bamboo/PLA pieces tomorrow.

As for your uses, I would really research what printer you would like to buy AND THE BRAND of bamboo/PLA filament you would like to buy. Some printers are better suited to handle fiber infused plastics than others, and most suppliers will let you know how their printer does with CF and/or bamboo infused plastics. Also, I wouldn't pigeon-hole yourself into using just PLA of any variation. One of the features I look for in a printer is the ability to use lots of different materials, and the ease of switching between these. This is one of the reasons I love using Lulzbots' Taz printers.

I have no empirical data (and really no practical experience) with using CF or bamboo infused plastics on desktop printers, but I have heard from people who do that bamboo provides a lot of the same benefits as CF, but since the bamboo fibers are softer, they are much less likely to scratch or cause extra wear on the printer hardware. Bamboo might not give as good a strength to weight ratio, or a lower tensile strength, but I think that bamboo-infused parts could be a great boon to users.

Also, echoing Lonnie's comment about the anisotropic properties. The CF and bamboo can actually make this difference in tensile strengths worse, not better, so be forewarned.